1. Field of the Invention
The present invention relates to an information processing apparatus that enables electronic watermarking, and a communication network that can be connected to such an information processing apparatus.
2. Related Background Art
To date, the functional performance of personal computers has been enormously improved, and the editing, referencing and printing processing required for image data have become comparatively simple tasks. In addition, since the use of networks, such as the Internet, is now widespread, and image data can thus be distributed and acquired easily and quickly, there has been a corresponding increase in the illegal use of image data, its editing and printing and its citing, done without the permission of the copyright holders.
To protect copyrighted image data and to prevent the illegal use of such material, a method has been proposed that involves the use of so-called electronic watermarks. According to one conventional copyright protection method for which electronic watermarks are used, to prevent the illegal use of low-resolution images, which are employed for displays or as editing samples, visible electronic watermarks are uniformly applied so that the value of the original images is not impaired. For high-resolution images that are employed for printing or for download sales, invisible electronic watermarks consisting of copyright holders' names or copyright display examples that can not be detected by human beings are also uniformly applied. Thereafter, the illegal use of the copyright material is prevented by notifying the provision of an electronic watermark. If an instance of illegal use is discovered, a detection means can be used to detect the electronic watermark, and the distribution route for an illegal image can be traced and unauthorized users identified.
That is, with one conventional copyright protection method, when an image is registered in an image processing system, an electronic watermark is uniformly applied in accordance with the purpose of employment and regardless of the will of the copyright holder.
However, when a number of images are handled for a plurality of copyright holders, the copyright protection measures that the individual copyright holders prefer will probably differ. For example, a first copyright holder may decide to abandon his or her copyright for a sample image and to permit the image to be distributed free, but may request that a high-resolution image receive strict copyright protection; whereas a second copyright holder may request strict copyright protection not only for a high-resolution image but also for a sample image. In this case, the desires of individual copyright holders can not be precisely satisfied by the conventional method, whereby at the time images are registered the same system is used to uniformly provide electronic watermarks.
Since conventionally an electronic watermark is applied only when an image if registered in an image supply system, which is responsible for the transmission of the data for the image to a plurality of users or print servers, if in some system illegal use is made of certain of this data, it is extremely difficult to trace the affected data because all copies of the image carry the same electronic watermark.